21405300386 has 8 divisors (see below), whose sum is σ = 32245753644. Its totient is φ = 10656715840.

The previous prime is 21405300379. The next prime is 21405300431. The reversal of 21405300386 is 68300350412.

It can be written as a sum of positive squares in 2 ways, for example, as 21350762161 + 54538225 = 146119^2 + 7385^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21405300386² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22966595 + ... + 22967526.

Almost surely, 2^21405300386 is an apocalyptic number.

21405300386 is a deficient number, since it is larger than the sum of its proper divisors (10840453258).

21405300386 is a wasteful number, since it uses less digits than its factorization.

21405300386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45934356.

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 21405300386 its reverse (68300350412), we get a palindrome (89705650798).

The spelling of 21405300386 in words is "twenty-one billion, four hundred five million, three hundred thousand, three hundred eighty-six".